grunt fails with "Warning: handlebars does not support render."

[positron]

Error message:

Running "assemble:styleguide" (assemble) task
handlebars does not support render.
Assembling dist/styleguide/index.html ERROR
Warning: handlebars does not support render. Use --force to continue.

Aborted due to warnings.

$ node --version
v6.3.0
$ npm --version
3.10.3

[positron]

I fixed this by adding a version to package.json. Example:

   "name": "whiteout-mail",
   "version": "0.1.0",